PAGE: gps

[jdehaan]

Distance

https://www.movable-type.co.uk/scripts/latlong.html
https://stackoverflow.com/questions/365826/calculate-distance-between-2-gps-coordinates

function degreesToRadians(degrees) {
  return degrees * Math.PI / 180;
}

function distanceInKmBetweenEarthCoordinates(lat1, lon1, lat2, lon2) {
  var earthRadiusKm = 6371;

  var dLat = degreesToRadians(lat2-lat1);
  var dLon = degreesToRadians(lon2-lon1);

  lat1 = degreesToRadians(lat1);
  lat2 = degreesToRadians(lat2);

  var a = Math.sin(dLat/2) * Math.sin(dLat/2) +
          Math.sin(dLon/2) * Math.sin(dLon/2) * Math.cos(lat1) * Math.cos(lat2); 
  var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a)); 
  return earthRadiusKm * c;
}

distanceInKmBetweenEarthCoordinates(0,0,0,0)  // Distance between same points should be 0
0

distanceInKmBetweenEarthCoordinates(51.5, 0, 38.8, -77.1) // From London to Arlington
5918.185064088764

Smoothing

• https://stackoverflow.com/questions/1134579/smooth-gps-data
• https://github.com/Hypercubesoft/HCKalmanFilter

Map matching

• https://github.com/graphhopper/map-matching
• https://en.wikipedia.org/wiki/Map_matching

Analysis

• http://utrack.crempa.net/
• https://www.topografix.com/gpx_resources.asp (maps)